Drug delivery system

Abstract

An ophthalmic drug delivery system is provided which includes at least one particle of bioerodible material, and a liquid or ointment carrier which includes ophthalmic drug to be delivered to the ocular area. A process of making the system and a method of treatment are also provided.

What is claimed is: 
     
       1. An ophthalmic drug delivery system including a composition comprising: one of a liquid carrier and an ointment carrier containing ophthalmic drug to be delivered to an ocular area and having a pH acceptable to the eye; and   at least one particle of bioerodible material in said carrier and including at least the same ophthalmic drug as in said carrier in the same chemical form.   
     
     
       2. A system as in claim 1, wherein said particles additionally include a different drug than said drug in said solution. 
     
     
       3. A system as in claim 1, including a plurality of said particles, at least a portion of said particles including drug in a different concentration than at least another portion of said particles. 
     
     
       4. A system as in claim 1, including a plurality of said particles, at least a portion of said particles including a different drug than at least another portion of said particles. 
     
     
       5. A system as in claim 1, wherein a specific equilibrium between drug in said at least one particle and drug in said particle carrier provides a specific amount of drug to be delivered over a specific duration when administered to the ocular area. 
     
     
       6. A system as in claim 1, wherein said bioerodable material is at least one member selected from the group consisting of collagen, gelatin, polyvinyl alcohol, polymerized methycellulose and methyl cellulose derivatives. 
     
     
       7. A system as in claim 1, wherein said ophthlamic drug is at least one member selected from the group consisting of idoxuridine, phenylephrine, pilocarpine and its acceptable salts, eserin, carachol, phospholine iodine, demecarium bromide, cyclopentolate, homatropine, scopolamine and epinephrine. 
     
     
       8. A system as in claim 1, wherein said ophthalmic drug is at least one ophthalmic steroid selected from the group consisting of hydrocortisone, hydrocortisone acetate, dexamethasone, desamethasone 21-phosphate, fluocinolone, medrysone, prednisolone acetate, fluorometholone, betamethasone and triamcinoline. 
     
     
       9. A system as in claim 1, wherein said ophthalmic drug is at least one antibiotic selected from the group consisting of tetracycline, chlorotetracycline, bacitracin, neomycin, polymyxin, granicidin, oxytetracycline, chloramphenicol, gentamycin, penicillin, erythromycin, tobra mycin, ciprofloxacin and norfloxacin. 
     
     
       10. Process for making an ophthalmic drug delivery system including a composition comprising: forming at least one particle of bioerodible material; and   suspending said at least one particle of bioerodible material in one of a liquid carrier and an ointment carrier containing ophthalmic drug to be delivered to the ocular area and having a pH acceptable to the eye;   said at least one particle when suspended including at least the same ophthalmic drug as in said carrier in the same chemical form.   
     
     
       11. A process as in claim 10, further including adding ophthalmic drug to said at least one particle of bioerodible material prior to suspending said at least one particle in said carrier. 
     
     
       12. A process as in claim 11, wherein said adding of drug to said at least one particle includes soaking said at least one particle in a solution containing the drug such that the at least one particle absorbs the drug. 
     
     
       13. A process as in claim 12, wherein said soaking solution is prepared with a specific concentration of drug, and said at least one particle absorbs a specific amount of drug depending on the specific concentration of drug in said soaking solution. 
     
     
       14. A process as in claim 11, further including establishing a specific equilibrium between the drug in said at least one particle and the drug in said carrier, thereby establishing a specific concentration of drug to be delivered and a specific duration of drug delivery when administered to the ocular area. 
     
     
       15. A process as in claim 10, wherein said suspending includes using least one of bioerodible material which absorbs said included in said carrier during said suspending. 
     
     
       16. A process as in claim 15, further including adding ophthalmic drug to said at least one particle of bioerodible material prior to suspending said at least one particle in said carrier.